Electron Correlations at Metallic Densities. V

In this paper we present a modification of an earlier theory of Singwi et al. of electron correlations at metallic densities. The modification consists in allowing for the change of the pair correlation function in an external weak field via the density derivative of the equilibrium pair correlation function. This results in a new expression for the local-field correction. The present theory has the merit of satisfying almost exactly the compressibility sum rule and of giving a satisfactory pair correlation function. Results of self-consistent numerical calculations for the static pair correlation function, correlation energy, compressibility, and plasmon dispersion relation for the electron liquid in the metallic-density range are presented. For those interested in the application of the results of the present paper, numerical values of the local-field correction as a function of wave number have been tabulated in the density range rₒ=1-6.